John J. Garrity was the chief of police in Chicago in the late 1910s and 1920. Key events during his tenure included the 1919 Chicago Race Riot and the murder of Jim Colosimo.
Indiana Jones met him in 1920 in Chicago after the murder of Indy's boss, Jim Colosimo. Garrity came to the crime scene at Colosimo's Restaurant and publicly announced his personal involvement in the investigation of the death of his friend Colosimo.
However, the official police investigation yielded little results. When Indiana Jones, Ernest Hemingway, and Eliot Ness provided key evidence to the chief that showed that Jim Torrio and Al Capone had conspired to have Colosimo killed, Garrity tore up their evidence and threw it away - showing that he was firmly in the pocket of Chicago's gangs.
This act of open corruption caused Ness, Hemingway, and Jones to all think about their careers, as well as prompt Ben Hecht to give up reporting and seek a career in writing.
Behind the scenes
??? played Garrity in the segment Chicago, May 1920 in Young Indiana Jones and the Mystery of the Blues now Chapter 20: The Mystery of the Blues.
In November 1920, he was forced to resign by Mayor Bill Thompson for being corrupt.